Page 7 - Opportunities in the Treatment of Water and Other Wast Streams
P. 7
• Low chemical demand
• Low energy demand
• Minimal maintenance, periodic removal of sediment is required • Minimal periodic operator oversight
• Capital costs in most producing area are generally low for land acquisition
Limitations:
• Large footprint
• Lack of mobility
• Poor removal of oil and grease
• Requires regulatory permitting (environmental protection)
Where: Commonly used in on-site facilities for storage and initial removal (where permitted) and as an integrated process at off-site facilities.
Target Contaminants:
Suspended solids
Iron and manganese (via oxidation from dissolved oxygen equalization with atmospheric conditions)
Organic chemicals naturally occurring or present in fracturing chemical (partially degraded through photolysis)
Higher removal efficiencies are possible by adding chemical addition (pH adjustment, coagulants, biocides, etc.)
Settling ponds use gravity to separate and remove suspended solids. Water flows across the settling pond with sufficient time for large particles to settle out. Particles that accumulate on the pond bottom are periodically removed and sent to landfills for disposal.
Settling ponds are open to the atmosphere and also provide some limited oxygen diffusion and photolysis (i.e., degrading chemicals via light and photons). However, complete degradation for organic compounds in a settling pond is unlikely. If photolysis occurs, it will likely only promote byproduct compound formations and subsequent organic compounds derivatives that will also need to be removed.
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